Magneto-electric machine



April 25, 1933. E. E. HOFFMAN 1,906,065

MAGNETO-ELECTRIC MACHINE Filed Oct. 2, 1929 5 Sheets-Sheet l A TTORNE Y.

April 25, 1933. E, E HOFFMAN 1,906,065

MAGNETOjELECTRIC MACHINE Filed Oct. 2, 1929 5 Sheets-Sheet 2 IN VEN TOR,

lar] Z.' Kaff/11m,

A TTORNE Y.

April 25, 19332` E, E HOFFMAN 1,906,065

MAGNETO-ELECTRIC MACHINE Filed Oct. 2, 1929 5 Sheets-Sheet C5 I lijf/f.;

l f i 1 INVENTOR, Zzf'l Haffffza/z,

A TTORNE Y.

April 25, 1933. E. E. HOFFMAN 1,906,065

MAGNETO-ELECTRI C MACHINE Filed Oct, 2, 1929 5 Sheets-Sheet 4 INVENToR,Ef/zr] E. Hoff/nmz,

BY @ZZ/vu; fw.

A TTORNE Y.

April 25, 1933. E, E, HOFFMAN l 1,906,065

MAGNETO-ELECTRIG MACHINE Filed 001;. 2,1929 5 Sheets-Sheet 5 BY ,Mw/m

ATTORNEY.

Patented A'pr. 25, 1933 UNITED fs'rATl-:s

E. HOFFMAN, OF SPRINGFIELD, MASSACHUSETTS MAeNETo-ELECTRIC MACHINEApplication led October 2, 1929. Serial o. 396,819.

This invention Vrelates to Vimprovements in magneto electric machines ofthe type in which a reciprocable ,f armature is employed for producing aquicky and sudden change in the magnetic flux.

My invention has for an object to provide, in any and all of the formsof the same, which are shown and describedin a magneto electric machine,a reciprocable l@ armature which is mounted for such movementi in aplane, which is located adjacent to the ends or poles of the cores, and,preferably, in close proximity to the ends of soft iron core pieces. Inthis type of magneto, it is very desirable that the movable armaturedoes not actually contact with the ends of the cores or other polepieces for various reasons, among which` may be mentioned is the entireelimination of noise, and

further to lessen the mechanical effort,

necessarily required to' Withdraw the armature from contact with thepole pieces, or in other Words, to overcome most of the magneticattraction. This is a formr of inagneto which now constitutes a part ofthe prior art.

A further object is to provide a magneto electro machine that permits ofslow speeds being imparted to the armature.

A further object is to provide means, not only for reciprocating thearmature, but also, to store up potential or dynamic energy in the formof a spring or springs, or other structure, Which When its stored energyis released, Will operate yto impart a decided impulsive or accelerativeaction to the armature and a quick reciprocable movement to the same,whereby the rate of change in the magnetic il'uX Will operate to `inducea high 40 voltage in the windings of the current generating coils of aspark circuit, `vvhen the magneto is employed for ignition purposes.

A further object, among others, isto so shape or form the reciprocablearmature and its co-operating pole pieces, forthe purpose of bringingabout a high rate of change in the magnetic flux in order that asecondary current of high voltage vmay be generated. In one 'form of myarmature, notches or recesses, are provided `which co-operate with 5othe pole pieces, either of a permanent magnet or the poles ,of soft ironcores. In another .orm of armature, the reverse is employed, namely,forming projections on the armature, which when operated, are movedclose to but not in actual contact vvith the pole pieces, orfaces of thesame.

In still another form of my invention, in which the same principle isinvolved, the armature is guided in its reciprocable movedo ments andthe poles are supported by a nonfcrrous metal.

Different modes, or structures for supporting and locating the primaryand secondary current kgenerating coils are employed, namely, Within thepoles of a fixed or permanent magnet, and, on a soft 0r laminated ironcore, in Which structure, a projection is formed on the armature Whichis located close to the poles of the said core.

A further embodiment of my invention resides in different means foractuating the reciprocable armature from some moving part of an internalcombustion engine, as eccentrics, cams With let-olf shoulders. Theexpansive force of a spring under Vcompression may be employed forreturning the armature, when actuated by an eccentric, a cam, or otherequivalent means. In this instance, a follow-up roller onthe armature S0may be employed' which engages the eccentric, cani or equivalent device.Independent means is provided for impartinganv accelerative movement tothe armature.-

' Suitable means areprovided for support- 85 ing the reciprocablearmature out of actual Contact With the poles or cores of the machine,as rollers, guide casings, as will be fully described in the body of thedescription, and pointed out in the claims.

In the drawings, which illustrate my invention, Fig. 1 is an elevationalview, partly in section, showing a conventional form of magneto with anarmature mounted for lateral reciprocation, adjacent the pole pieces.

Fig. 2 illustrates the first position of the armature shown in Fig. 1,after its movement towards the left hand.

Fig. 3 illustrates a second position of the armature towards the righthand.

Fig. 4 is a detail view of one form of a make and break mechanism, whichis actuated from the armature during its reciprocation.

Fig. 5 is a cetail view of a modification in which projections areemployed on the armature and any suitable means is understood to beemployed for reciprocating the armature.

Fig. 6 illustrates an eccentric drive for the armature with acompression spring for following up the movements of the eccentric.

Fig. 7 is a. detail end View on the line 7 7 of Fig. 8 showing a furthermodification in which the reciprocable armature is guided and supportedin a casing and which armature is located adjacent the inner verticallyarranged pole pieces.

Fig. 8 is a bottom plan view of Fig. 7 showing the armature and itssupporting casing and guide and the laminated pole pieces.

Fig. 9 is a view of a let-oit' tuating the armature.

Fig. 10 is a detail plan view armature of Fig. 8 removed.

Fig. 11 is a detail view of a. modification ofthe armature, shown inFig. 8 with projections.

Fig. 12 illustrates a form in which apermanent magnet or a permanentsource of magnetic flux is reciprocated across the ends of the core.

Fig. 13 is an end view of Fig. 12.

Fig. 14 is a view of a further modification in which the pole ends ofthe core are turned inward into a horizontal plane and a reciproca'blepermanent magnet located therebetween.

Fig. 15 is a sectional view on the line 15-15 of Fig. 14.

Fig. 16 illustrates a. further modification in which the primary andsecondary coils surround the reciprocable armature which coils arelocated between the poles of a permanent magnet, and the armature isreciprocated in close proximity to the poles.

Fig. 17 is a side elevational view of Fig. 16.

Fig. 1S is a sectional view considered in a vertical plane illustratinga reciprocable armature formed with notches, and a coil having primaryand secondary windings, and

cam for acshowing the oppositely located permanent magnets havinglaminated pole pieces, located adjacent the notches of the armature.

Fig. 19 illustrates a device or means for positioning the acceleratorinto and out of? operative engagement with the armature.

Fig. 20 is a modification of means for imparting an impulse oraccelerative efl'ect to the armature.

Figs. 21, 22 and 23 show details of a modification of the usual drivingconnections of an armature of a magneto assembled in an enclosed magnetostructure.

Referring to the drawings in detail, 1 designates a permanent magnet ofthe bar type for supplying a fixed or permanent magnetic flux. Severalof these may be arranged side by side to form a compound magnet. 2designates the soft iron laminated core pieces which are secured to theends of the permanent magnet 1 in any suitable way (not shown). Thepoles of the soft iron core pieces 2 are indicated at 3, which areconnected together by means of the bar 4 of non-magnetic material. 5designates an armature composed of lamina` tions of soft iron, which ismounted for lateral or other directional reciprocation in the bearingpieces 6, 7 8 and 9 and in close proximity to the poles, 3, whichproximity distance may be any desirable one. These bearing pieces areshown as being located in and supported by the enclosing casing 10,preferably of bakelite or other non-mag netic material, which may bemolded. The armature 5 is formed with cutout or recessed portions l1 and12, the length otl which recessed portions is greater or less than thewidth of poles 3 of the core pieces 2, or varied as experiment maydetermine. Suitable means is provided for reciprocating the armature 5,from aI conveniently located and moving part of a machine with which itis associated, as an internal combustion engine, which utilizes thespark current generated in the secondary windings of the currentgenerating windings.

As shown, a depending member 13 is secured to the armature 5 to whichthe link 14 is pivotally connected at 15. This link is secured to theeccentric 16, 17 being the operating shaft and 18 the strap whichencircles the eccentric 16 that is connected to the link 14.

In Fig. 2, the armature 5 is shown approximately in its first position,after being moved towards the left hand. In this po` sition, the poles 3ot the cores 2 are opposite the two projections 19 and 2O of thearmature. The magnetic flux in this position is now established, orclosed, from the permanent magnet 1, through the cores 2 and through theprojections 19 and 20.

As the armature 5 is moved in the opposite direction from that shown inFig. 2, the

permanent magnetic iux or circuit iS quickly broken, as thel recesses11l and 12 are` moved relative to the poles 3 of the cores 2, wherebyacurrent of high voltage is generated in the secondary coil of thegenerator windings, shown in Fig. 1, at 21 and 22. The rate of change ofthe magnetic ux is very rapid as the corner portions 5 and 5 ofy thearmature 5 pass the adjacent corners 3 and 34'", or in other words, thepeaky of the electromotive torce of the induced current would, ofcourse, occur at the instant that these corner portions ot the armatureand pole pieces of the cor-e pass by or are moved relative to each otherin rapidy succession and in close proximity to each other. The inducedcurrent would be substantially a continuous one for the reason that theflux of the magnetic circuit is practically a continuous one. ,It is, ocourse, obvious that the rate of change ofthe lines ot' force in themaking and breaking of the magnetic circuit is dependent upon the rateof reciprocative movement ot the armature 5. Figs. 44 and 18 illustrate`the opening and closing of the circuit by the armature.

In Fig, 4, shown, the reciprocable laminated armature actuates themakeand break device of the primary circuit (see Fig. 23) whichcomprises the fixed and movable contacts 18 and 24, the movable contactbeing carried by the lever 25 which is pivotally supported at 26. Anexpansion spring 27 normally closes the primary circuit in the usualmanner. The projection 28 on the armature engages the curved hook part29 and actuates the lever 25 which opensy the circuit, when it isreciprocated in both directions, the first position being indicated byrthe arrow in full line and the second position by the arrow in thedotted line.

In Fig. 5, the reciprocable armature 30 instead of being formed withrecesses, as 11 and 12, is formed with the two projections 31 and `32,the width of which projections are substantially equal to the width ofthe poles 3 of the core pieces.` On each side of these projections,there is formed the recesses 30, 30 and 30". A suitable operating rod 3lis shown attached to the armature 3.() for reciprocating the salne, theprojections of which are designed to move in very close proximity to thepoles 3 for reducing the reluctance of the magnetic flux by utilizing assmall an air gap as possible. It will be seen that when this formofarmature is in the position shown, the magnetic circuit is complete,when it is reciprocated into this position by the rod 31. The greatestrate of change in the magnetic iluxr will occur, as the cores of thevpoles and the corvners of the projections of the armature are 4movedpasty each other, the depressions in rthe armature serving tomomentarily break the magnetic flux.

In 6, is shown an eccentric 32 onthe shaft. 33. Engaging the peripheryof the eccentric is ay roller 34 which is connected or attached to thelaminated soft iron arma.- ture 30. 35 is an expansive springV which,whenl the armature'is moved toward the left hand end of the figure, iscompressed and then gradually expands on the return movement to causethe armature to follow up the rmovements of` theeccentric.

In Figs. and 8, is Villustrated a further modification of the magneto`construction The armature 36, shown in detail in Fig. 10, comprises `aat member of laminated iron with the recesses, 37 and 38. Thesevrecesses are located opposite the laminated cores 39 and 40 on whichthe current generating coils 41 and 42, shown. in dott-ed linesl y(Fig.8)., are pla-ced. These, laminated cores are secured together by meansof the bolts 43 which at the same time secure the casing members 44 andy45 together. The armature 3G" is mounted for reciprocating movements inguide or casing members 44 and 45 that that are secured to the poles 394and 40 by means ofthe bolts 43.y Y An armature operating link isshown at48, which is connected to the armature by means of a pin, indicated at49. It will be noticed in Figs. 8 and 10 that` the recesses 37 `and38are slightly wider than the width of the poles of the cores, and thatthe armature passes in close proximity to the vertical inner sides 39and 40 of the poles of the cores, whereby the fluxy through these coresand `poles is rapidly changed, as the. armature is reciprocated.

Fig. 9 shows a let-off cam for imparting a reciprocating movement torthe armature, shown in Fig.y 6, the let-0H portion being indicated' at50.

In Fig. 11, an armatureBG is shown with the projections 51, that areapproximately of the same length as the width of the. core pieces 39 and40.

Referring to Figs. l2 and 13, the reciprocable armature 52 comprises apermanent magnet having the soft iron pole pieces or projections 53 and54 secured thereto which are preferably laminated. These projections arelocated, as"before,`in close proximity tothe pole ends55 and 56 of theU-shaped core. The primary and secondary coils, indicated at 5.7 and 58,are located on the U-shapedvcore. In this construction, the magnetic uxfrom the permanent magnet, as the same is reciprocated, will inducecurrents in the primary and secondary coil windings, it beinglunderstood that the .primary circuit of the windings is made and brokenby a part which is attached` to the armature 52,'as indicated in Figs. 4and 18@l In Figs. 14 and 15, a reciprocable ypermanent, magnet 59 isshown which is located between the ,inwardly extendingv pole ends 60andi 61` of the soft iron. laminated cores.

The primary and' secondary current generating coils are indicated at 62,which are mounted on the connecting yoke piece 63, whereby the magneticux is completed through the permanent magnet 59 and the sott iron pieces60', which are secured to the pole ends of the permanent magnet.

In Figs. 16 and 17 is shown a construction in which the permanent magnetemployed, the poles of which are provided with the laminated pieces 71for concentrating the lines of force. 72 is a reciprocable armaturebuilt up of soft iron laminations and formed with the recesses 73 and74. This armature is located in and passes thru an aperture 75 of theprimary coil 76. 77 designates the secondary coil. Any suitable meansInay be provided for supporting the coil windings within the permanentmagnet. Suitable means, as the link 78, is provided for reciprocatingthe armature, so that the recesses 73 and 74, pass into and fromregistration with the pole pieces 71, to cause a high rate of change inthe magnetic flux, as the corners 5 and 5 pass by the corners 71 and 71.It is obvious that when the armature is reciprocated, electric currentsare generated in the coils 76 and 77 and that the primary circuit ismail@l and broken by the movements of the armature by means o1 astructure similar to that already referred to in connection with Fig. 4.

Fig. 18 illustrates a further modification which may be considered asbeing located in either a horizontal or in a vertical plane. Itcomprises two sets of permanent magnets 89 and 90. Secured to the polesof magnet 89 are the laminations of soft. iron 91 and 92 that aresecured together with the screws, bolts or rivets 93. Secured to thepoles of the permanent magnet 90 are the laminations ot soft iron 94 and95 which are secured together with the screws, bolts or rivets 9G. 97and 98 designate the primary and secondary windings respectively of thecurrent inducing coils. The reciprocable armature, indicated at 99, isformed with the two sets of depressions 100 and 101; 102 and 103, whichare arranged opposite the respective polar extensions. The electricalconnections comprise the wires 23 and 23, which are connected to theprimary windings 97, one wire being grounded by the line, indicated at23'", and, the otner wire connected to the movable contact 24. 24 is acondenser connected across the terminals 23 and 24 with the wires 24 and24', which is grounded at 26.

Referring to Fig. 19, 101 and 105 desig nate the soft iron cores onwhich the current generating coils 106 and 107 are placed. 108 indicatesa reciprocable armature having the depressions 109 and 110, which aredesigned to register with the poles of the cores, as the armature isreciprocated in close proximity to their lower ends, as shown. In thisfigure, means are shown for imparting an impulsive or quick accelerativemovement to the armature at the end of its travel in either of itsdirections. This means, as one form comprises an adjustable plate,indicated at 111, the adjustment consists ot the screw and slotconstruction 112. Pivotally mounted on this plate, is a two arm lever113, the pivot being indicated at 114 on the plate. 115 and 116 are twocoiled compression springs between the inner ends of which one end ofthe lever 113 is placed. Located within the springs is a block 113 whichis secured to this lever, its other end is located in the path of thepart 117 which is secured to the armature 108. 118 is an operating rodthat is considered as being connected to some moving part of an internalcombustion engine for reciprocating the armature. On this rod are thetwo sleeves 119 and 120. 121 designates two sets of nuts tor positioningand locking the sleeves at a definite position on the rod 118 tervary/'ing the tension ot the springs 122 and A123. The compressionsprings 122 and 123 are located on these sleeve. Located between theinner ends of these springs is a depending part 121 which is lixedlysecured to the reciprocable armature 108. The operation ot thisconstruction as follows: lllhen the rod 11S moves in the direction oithe arrow 125, the spring 123 is being compressed, until the part 121engages the end of the sleeve 120, which acts as a stop. At the sametime, the lever 113 is actuated by the rigid part 117 and compresses thespring 110. As the rod 118 continues, its movement, the part 117 will beforced past the lower end of lever 113, which will, of course, assnn'iea position on the opposite side of 117. 1n the meantime, as the spring123 has been compressed, it is now free to recoil, which it will do andimpart an impulsive accelerative movement to the armature 108, causingla high rate oit change in the magnetic tlux to take place, as thecorners 5 and 5 of the depressions 109 and 110 pass the corners 3 and 3of the poles 101 and 105, with the result that a high voltage will beinduced in the secondary winding ot the current generating coils 10G and107. The springs 115 and 11G operate, in a meas ure, to cushion thepartsI during the movements. The reverse operation is apparent, as thespring' 122 and the sleeve 119 will operate in t same way, as beforedescribed. I do not li; it myself to the construction of the adjustableplate 11, as shown. It should be stated, in connection with Fig. 19,that the plate 111 is for the purpose ot' sliding or adjusting theaccelerator into and out of engagement, it' desired. In Fig. 20, analternative construction is shown for imparting an -accelerativemovement to the armature 108, which comprises the brackets 126 attachedto the armature 108, to which is secured the rod 127 and on which rodthe sleeves 119 and 120 and the compression springs 122 and 123 arelocated. Instead of rod 118,' shown in Fig. 19, I employ the operatinglink 129. The bracket arm 128 is slidably mounted on the fixed rod 127In this construction, the springs 122 and 123 and the sleeves 119 and120 will operate in the same manner as before-described, as the member128 slides on the rod 127 In practice, the rod 127 may be slidablyymounted inthebrackets 126 and the member 128 secured lto the rod 127.It will be seen from all of these views that they all embody theprinciple of moving an armature in close proximity to poles, rwhereby arapid rate of cutting the magnetic lines kof force may be obtained.

Referring to Fig. 21, the recessed armature 13()l is reciprocated inopposite directions by means of the link 131 which is attached to thewheel 132 that is understood to be operatively connected to some movablepart of an internal combustion engine (not shown).

In Fig. 22 is shown va further modification in which the armature 133 isoperated by means of tHe bracket arm 134 having a slot 135 in which adrive pin 136 is located. This pin is carried by the wheel 137 which isalso yoperated by and from an internal combustion engine (not shown).

In Fig. 23, is shown a casing 140 for enclosing the magneto electricmachine illustrated in Fig. 1. In this' construction, the armature 5 isreciprocated vby means of the link 141 which is pivotally connected tothe armature at 142 and to the wheel 143 at 144. The tapered part 139 isunderstood to be o 'eratively connected to some moving part 0I aninternal combustion engine. (Not shown.)

In other words, the construction shown in Fig. 23 is a driving mechanismfor the armature which is located in or associated with the magnetgroup.

It is to be understood that projections on the armatures 130, 133,shownin Figs. 21 and 22 and the armature 5, shown in Fig. 5, may be providedwith projections.

It is to be understood` that I do not limit myself to the details ofinvention shown and described as obvious equivalent structure whichproduce the `same results are included. I wish it tobe understood thatbroadly my improvement comprises a reciprocable armature having recessesor projections which is reciprocated in close proximity and relative tothe poles of a permanent magnet, and soft iron cores on which generatingcoils are placed. It is also to be understood that a permanent magnethaving projections or recesses is reciprocated in close proximity ormovable relative to the cores on which` current generating coils arelocated. By the term movable past, as applied to the reciprocablemember, with soft iron or a permanent magnet, it is to be understoodthat the corners of the notches or projections move past thecorresponding corners of the generating coil cores or permanent magnetpoles, whereby a high rate of change of the magnetic flux is producedand high potential developed in the generating coils.

What I claim is:

l. A magneto electric machine comprising in combination, a permanentmagnet, core members having polar projections magnetically associatedwith the said permanent magnet, current generating coils on the coremembers, a reciprocable armature located in close proximity tothe polarprojections of the core members and having its cross section ofnon-uniform area from end to end for varying the reluctance of themagnetic flux in the said core members, means for imparting anaccclerative movement to the said armature, when the same is operated,for creating a high rate of change in the reluctance of the magneticcircuit, whereby an electric current of varying voltage is produced inthe generating coils.

2. In a magneto electric machine, the combination with a permanentmagnet, a core located within the magnet and magnetically associatedwith the permanent magnet, a reciprocable armature having projectionswhich are in the magnetic circuit of the core and in-close proximitythereto, current inducing coils on the core, means for reciprocating thearmature for varying the reluctance ofthe magnetic flux through ythecore.

3. A magneto electric machine comprising a core member, currentgenerating coils on said core member, a reciprocable permanent j magnetlocated between the polar projections of the core members for varyingthe reluctance of the magnetic circuit in the core members. i

4. In a magneto-electric machine, a permanent magnet having polarprojections, an armature, cores with current generating coils, means forsupporting and guiding the armature for reciprocation relative to thecores and polar projections, said armature having projections spacedfrom each other which are located in close proximity to the polarprojections, whereby the reluctance of the magnetic flux will bechanged, when the armature is reciprocate'd.

5. In a magneto electric machine, a plurality of permanent magnetshaving polar projections arranged in opposed yrelation with reference totheir opposite polarity, current generating coils magneticallyassociated with the kpermanent magnets, an armature having two sets ofnotches or recesses which are adapted to register with the opposed polarprojections ot' the permanent magnets, the coils being formed with anopening to receive the armature, and means for movi ng the armature inthe coils, and in close proximity with the polar projections of thepermanent magnets.

6. In a. magneto electric machine, a per manent magnet, coil cores,current generating coils on said coil cores and magnetically associatedwith the pole pieces of the permanent magnet, a recessed armature, meansoperatively connecting the armature with a moving part of an internalcombustion engine for reciprocating the same in close proximity to thepolar projections.

7. A magneto electric machine having a permanent magnet, and wherein anarmature is reciprocably mounted in close proximity with reference tocores on which coil windings are mounted, the armature having offsetportions which form corners that are moved relative to the polarprojections ot' the permanent magnet for varying the reluctance oi' themagnetic flux in the cores and the current generated in the said coilfor generating a high voltage in the Windings.

8. In an electro magneto machine, generating coils, cores on which thecoils are mounted, a reciprocable permanent magnet being;l mounted inclose proximity to the cores, the permanent magnet having oifsetportions at its poles and opposite the cores, to vary the magnetic fluxas the otfset portions of the permanent magnet are moved in recirocation relative to the cores and means or reciprocating the permanentmagnet.

9. In an electro magneto machine, an armature Witli ol'lset portionsinovably mounted for reciprocation relative to the generating coil coresand permanent magnet pole pieces to vary the flux, said armature beingin close proximity to the polar projections, means to accelerate themotion of the armature relative to the core ends from a predeterminedpoint to vary the flux with greater rapidity.

l0. In combination, a magneto electric machine comprising, a permanentmagnet having pole pieces, core members, polar projections on the coremembers magnetically associated with the pole pieces of the permanentmagnet, current generating coils on the core members, an armatureconsisting of ferrous metal only and mounted for reciprocation in astraight. line and in close proximity to the polar projections olE thecore members and formed With projections which serve to vary thereluctance of the magnetic flux in the cores as the armature isreciprocated.

l1. In a magneto electric machine, a re ciprocable armature composed offerrous material having projections arranged on oppositc sides, coreshaving polar projections, current generating coils mounted on the cores,the sides of the armature being in close proximity to the polarprojections, whereby when the. armature is reciprocated, the reluctanceof the magnetic flux will be varied in said coils as the projections arereciprocated relative to the polar projections ot the cores, and meansfor reciprocating the armature.

l2. In combination, in a magneto electric machine, a permanent magnet, areciprocable armature composed of ferrous metal, projections formed onthe armature guides for movably supporting the armature and in closeproximity to the polar projections ol the magnet cores associated withthe permanent magnet, current generating coils on the cores, means forreciprocating the armature and moving the projections into and out oi'the magnetic flux in the cores.

13. In a magneto electric machine, in combination, a permanent magnethaving polar projections, core members magnetically associated with thepolar projections, current generating coils on the polar projections ot'the permanent magnet and core members, an armature formed with recessesor projections and located in close proximity to the core members andpolar projections, a let-off device operatively connected to thearmature for moving the same in one direction relative to the polarprojections, and a follow-up means for the armature for impartingaccelerative movement to the armature.

14. In a magneto electric machine, a permanent magnet having polarprojections, au armature, cores with coils magnetically associated withthe magnet, means for supporting and guiding the armature forreciprocation between the polar projections, said armature having offsetportions at opposite sides which are located in close proximity to thepolar projections, whereby the magnetic flux will be changed, when thearmature is reciprocated.

15. In combination, a magneto generator comprising, a permanent magnet,core members having polar projections in magnetic circuit relation withsaid magnet, generating coils mounted on the core members, areciprocable armature composed of ferrous metal only and provided withoffset projections for co-operation with said core members and in closeproximity to the core pro` jections when the armature is reciprocatedfor varying the current induced in the said generating coils. f

16. A magneto electric machine comprising, in combination, a permanentmagnet, core members having polar projections and in magnetic circuitrelation with said magnet, current generating coils xedly Secured on thecore members, a reciprocable armature consisting of ferrous metallocated in close proximity to the said polar projections, and having itscross section oiE non-uniform area for varying the reluctance of themagnetic flux in the core members, whereby an electric current isproduced in the generating coils, when the armature is reciprocated.

17 In combination, a magneto electric machine, a magnet having polepieces, core members magnetically associated with the said magnet,current generating coils ixed on the core members, a reciprocablearmature provided with projections which are located in close proximityto the polar projections of said core members and having its crosssection of non-uniform area for varying the reluctance of lthe magneticflux in the core members, the projections of said reciprocable armatureoperating for varying the reluctance of the magnetic circuit through thesaid generating coils when the armature is reciprocated and whereby anelectric current is produced in the generating coils.

18. In combination, in a magneto electric machine, an enclosing casing,a permanent magnet, core members having polar projections and inmagnetic circuit relation with said magnet, a reciprocable armature,bearings for the said armature for constantly maintaining the same inclose proximity to the polar projections of the core members, currentgenerating coils secured on the core members, means for actuating thearmature, and means for imparting an accelerative movement to thearmature during the travel of the same.

19. A magneto electric machine, comprising in combination, a permanentmagnet, core elements magnetically connected to the said permanentmagnet, current generating coils on the core elements, an armature Withoffset projections Which are arranged for reciprocation in closeproximity to the polar projections of the core elements, and means forreciprocating the armature.

20. In a magneto electric machine, a permanent magnet, provided withpolar projections, soft iron pieces secured to the polar projections ofthe permanent magnet, current generating coils magnetically associatedwith the said permanent magnet, an armature provided With offsets andmounted for reciprocation in close proximity to the said soft ironpieces, the offsets being constructed and arranged for varying thereluctance of the magnetic circuit in the coils, the current generatingcoils having an opening therethrough and in Which opening the saidarmature is located, and means for reciprocating the armature.

21. The combination, in a magneto electric machine, a permanent magnetprovided With polar projections, a reciprocable armature having oppositeside offset portions, a curcoil.

EARL E. HOFFMAN.

